1. Technical Field
The present disclosure relates to an audio reproduction device capable of correcting speaker characteristics in accordance with the model of a speaker unit when the device is connected to the speaker unit having the speaker and an audio reproduction method thereof.
2. Description of the Related Art
In recent years, portable phones having music reproduction capabilities and portable digital music players have been popularized. With this popularization, these portable music players are often connected to a docking speaker so as to reproduce sound. In general, a portable music player has only a small-diameter speaker or even does not have a speaker. However, by connecting the portable music player to a docking speaker which is a relatively large-diameter speaker, it is possible to reproduce audio signals output from the portable music player with high quality or at a high volume.
When sound is reproduced from such a docking speaker, signal processing is performed on the audio signals at the inside of the portable music player, whereby the speaker characteristics can be corrected. The speaker characteristics include frequency characteristics, distortion, transient characteristics, and directional characteristics which depend on the structure of the speaker. If these characteristics of a speaker used as an audio output device are known in advance, they can be corrected by signal processing.
Even when the characteristics of a speaker used as an audio output device are unknown, the characteristics of the speaker can be calculated by collecting sound output from the speaker through a microphone and corrected by signal processing. For example, JP-A-2008-282042 (paragraph [0078], FIG. 7) discloses a “reproduction device” which includes a microphone and corrects the characteristics of a speaker based on a test sound that is output from the speaker and collected by the microphone.
When no object affecting the transfer of sound is present between a microphone and a speaker, it may be possible to correct the speaker characteristics by the technique disclosed in JP-A-2008-282042. However, if an object affecting the transfer of sound is present between the microphone and the speaker, such correction may not be possible. In such a case, when the speaker characteristics are corrected by the technique disclosed in JP-A-2008-282042, it is necessary for a device (hereinafter referred to as a correction device) that performs the correction to acquire the positional relationship between the microphone and the speaker. That is, unless the correction device has the positional relationship, it may be difficult to separate the influence of the speaker characteristics on the sound collected by the microphone and the influence received during propagation of sound waves through a space.
When the characteristics of a docking speaker are corrected by a portable music player, the combination of the docking speaker and the portable music player may come in various configurations. In addition, in a state where a portable music player is mounted on a docking speaker, as a result of this configuration, it is highly likely that an object or the like which affects the transfer of sound is present between the microphone of the portable music player and the speaker of the docking speaker. For this reason, in many cases, it may not be possible to specify the positional relationship between the docking speaker and the microphone provided in the portable music player. Thus, it is difficult to correct the characteristics of the docking speaker using the signal processing of the portable music player.
It is therefore desirable to provide an audio reproduction device and method capable of correcting speaker characteristics in accordance with the model of a speaker unit.